鲁西北西向断裂系与沂沭断裂带晚中生代演化关系及其动力学背景探讨

晚中生代是华北地块构造演化的转折时期。由出露于沂沭断裂带、鲁西地体、鲁东地体的中生代地层、岩浆,结合断裂活动年代学、区域地质等资料分析,可以将沂沭断裂带晚中生代构造演化划分出距今约160Ma、130～110Ma、90～80Ma等3个关键时期,并分别与左行压剪、左行张剪、右行压剪构造活动相对应。晚中生代沂沭断裂带与鲁西北西向断裂系间的几何学、运动学、年代学的共轭匹配关系表明,它们为特定构造动力学背景下形成的一组共轭断裂系。同时对鲁东地体晚中生代构造演化、鲁东北西向断裂系特征,以及沂沭断裂带、北西向断裂系晚中生代构造演化的动力学背景进行探讨。

Relationship between NW faults of West Shandong and Yi-Shu fault zone in Late Mesozoic and their geotectonic setting operations

The Late Mesozoic was a turning point in the course of tectonic evolution of the North China Block.Structural events of Yi-Shu fault zone during this time may be divided into three periods:160 Ma B.P.,130-110 Ma B.P.and 90-80 Ma B.P.,which correspond to the fault movements of transpressional sinistral strike-slip,of transtensional sinistral strike-slip and of transpressional dextral strike-slip,respectively.Geometric,kinematic and chronologic analysis between Yi-Shu fault zone and north-west faults showed that they can be categorized as the conjugate faults during the late Mesozoic.In this article,we also discussed the dynamic mechanisms of NW faults and Yi-Shu fault zone movements in the late Mesozoic,including the structural evolutionary history and the characteristics of NW faults in east Shandong.